Electromagnetic relay



Jan. 9, 1940. MU L 2,186,340

' ELECTROMAGNETIC RELAY Filed Feb. 25, 1937 INVENT OR. KONRAD MULLERATTORNEY.

Patented Jan. 9, 1940 PATENT I OFFICE 2,186,340 v ELECTROMAGNETIC RELAYKonrad Miiller, Berlin- Spandau,

Germany, as-

signor to Siemens a Halske Aktiengeleliachaft,

Wernerwerk, Siemenntult,

many

ear Berlln, Ger- Application February 25, 1937, Serial No. 127,581 InGermany March 14, 1936 The invention relates to electromagnetic relaysand-especially for those used in telephony and having an angle armaturemounted on a knife edge.

5 Relays or this kind are already known in which in order to be able toadjust the release period, the armature is provided with a distanceplate instead of a so-called distance pin. If such a lo distance plateis to be exchanged for another larger or smaller plate in order to varythe release period of the armature then in the known embodiments acorresponding alteration of the travel of the armature was involved andthis rendered necessary considerable and therefore undesix-able bendingof the armature.

The invention relates to an arrangement in which the armature travelremains unaltered independent of the size of the distance plate.According to the invention this is achieved in that o the distance platestretches to the lower edge of the yoke and preferably as far as theedge on which the armature is mounted. By this means on altering thesize of the distance plate the point of pivotation of the armature isalso altered in correspondence with the size of the distance plate sincewith this arrangement the distance plate constitutes the armaturebearing surface as the armature rotates about theupper edge of the yokewhich forms the knife edge bearing for the armature. This has theadditional effect that the magnetic circuit is not only altered at thepole piece of the armature when a distance piece is exchanged but alsoat the point of mounting of the armature.

The invention is illustrated in the drawing by way of three embodiments.Only those parts of the relay are shown which ,are necessary forunderstanding the invention. V

In all the figures the armature I is shown in the attracted position.The distance plate 2 in the embodiment shown in Fig.1 consists ofnonmagnet material, for example of brass. It. is fixed to the armature Iby one or more screws 3 which at the back of the distance plate engagein a plate 4 and hold this fast against the distance plate. The plate 4at one of its ends extends close to the pole of the core 5 and its otherend extends close to the yoke l in order to clamp the distance plate'2as closely as possible against the surface of the armature i above boththe pole surface and the bearing edge 6. To increase this effect thedistance plate 2 may conveniently be pre-tensioned by bending, the plateslightly so that when the clamping plate 4 is screwed up tightly theouter edges of the distance plate will be exerting pressure against theunderside of the armature. The tension plate I can consist of magneticmaterial so that it may serve at the same time for influencing themagnetic lines of force passing between the core and the yoke. 5

Fig. 2 shows a relay having a distance plate of a difl'erentconstruction. The distance plate used in this case comprises two parts2a and 2b having different properties. Only the lower portion 2bassociated with the pole of the armature 10 is formed of non-magneticmaterial, the other portion 2a, which forms thesurface that engages theknife edge of yoke 1, consisting of iron. Any possibility of influencingthe lines of force of the magnetic circuit at this point is therebypre- 1. vented. The attachment of the two parts of the distance plate isthe same.

Fig. 3 represents a relay in which in addition to the actual distanceplate 2 an additional plate 8 is employed. This latter plate, which maycon- I) sist either of magnetic or non-magnetic material, may be of anythickness desired in order to alter the distance between the armature land the knife edge of yoke l' and thereby change the travel of thearmature.

With this arrangement a simple alteration of the armature travel is madepossible by merely exchanging the additional plate 8 while leaving thedistance plate. 0

As may be seen from the foregoing description these arrangements enableadjustments of the air gap and armature travel of a relay of this sortto be made in a simple way.

What is claimed is: u

1; In an electromagnetic relay, a pivotal armature, a yoke having aknife edge forming the fulcrum for said armature, a non-magnetic spacerplate on said armature for preventing the armature from contacting thecore of said relay and 0 extending along said armature to form thesurface that engages the knife edge upon which the armature pivots onsaid fulcrum, and a retaining plate mounted on said armature between thecore of said relay and said yoke for clamping said a spacer against saidarmature.

2. In an electromagnetic relay, a pivotal armature, a yoke having aknife edge forming the fulcrum for said armature, a spacer plate formedin two parts, one of said parts consisting of mag-- 50 netic material,said plate mounted on said armature so that it prevents the armaturefrom directly contacting the core of said relay and so that the magneticportion of said plate extends along said armature to form'the surfacethat engages 10 ing beyond the knife edge of said fulcrum to form thesurface that engages the knife edge upon which said armature pivots, andmeans whereby said second spacer plate can be removed and another spacerplate of different thickness 15 may be substituted therefor to alter theamount of travel of said armature about'its pivot point.

4. In an electromagnetic relay, a pivotal armature, a yoke having aknife edge forming the fulcrum for said armature, a first spacer platefor said armature to prevent the same from freezing against thev core ofsaid relay and extending beyond the knife edge of, said fulcrum, asecond spacer plate on said first plate and extending beyond the knifeedge of said fulcrum to form the surface that engages the knife edgeupon which said armature pivots, means whereby spacer elements ofdifferent thicknesses may be substituted for said spacer elements, the.distance of said travel of said armature about said pivot pointremaining the same with different thicknesses of said first spacerelement, and the distance of travel of said armature about said pivotpoint being altered with said second spacer element. a

- KONRAD MULLER.

